Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 220 insertions, 0 deletions

diff --git a/layout/base/MobileViewportManager.h b/layout/base/MobileViewportManager.h
new file mode 100644
index 0000000000..1d4fba1d54
--- /dev/null
+++ b/layout/base/MobileViewportManager.h
@@ -0,0 +1,220 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MobileViewportManager_h_
+#define MobileViewportManager_h_
+
+#include "mozilla/Logging.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/MVMContext.h"
+#include "mozilla/PresShellForwards.h"
+#include "nsCOMPtr.h"
+#include "nsIDOMEventListener.h"
+#include "nsIObserver.h"
+#include "Units.h"
+
+class nsViewportInfo;
+
+namespace mozilla {
+class MVMContext;
+namespace dom {
+class Document;
+class EventTarget;
+}  // namespace dom
+}  // namespace mozilla
+
+class MobileViewportManager final : public nsIDOMEventListener,
+                                    public nsIObserver {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIDOMEVENTLISTENER
+  NS_DECL_NSIOBSERVER
+
+  /* The MobileViewportManager might be required to handle meta-viewport tags
+   * and changes, or it might not (e.g. if we are in a desktop-zooming setup).
+   * This enum indicates which mode the manager is in. It might make sense to
+   * split these two "modes" into two separate classes but for now they have a
+   * bunch of shared code and it's uncertain if that shared set will expand or
+   * contract. */
+  enum class ManagerType { VisualAndMetaViewport, VisualViewportOnly };
+
+  explicit MobileViewportManager(mozilla::MVMContext* aContext,
+                                 ManagerType aType);
+  void Destroy();
+
+  ManagerType GetManagerType() { return mManagerType; }
+
+  /* Provide a resolution to use during the first paint instead of the default
+   * resolution computed from the viewport info metadata. This is in the same
+   * "units" as the argument to nsDOMWindowUtils::SetResolutionAndScaleTo.
+   * Also takes the previous display dimensions as they were at the time the
+   * resolution was stored in order to correctly adjust the resolution if the
+   * device was rotated in the meantime. */
+  void SetRestoreResolution(float aResolution,
+                            mozilla::LayoutDeviceIntSize aDisplaySize);
+
+  /* Compute the "intrinsic resolution", which is the smallest resolution at
+   * which the layout viewport fills the visual viewport. (In typical
+   * scenarios, where the aspect ratios of the two viewports match, it's the
+   * resolution at which they are the same size.)
+   *
+   * The returned resolution is suitable for passing to
+   * PresShell::SetResolutionAndScaleTo(). It's not in typed units for
+   * reasons explained at the declaration of FrameMetrics::mPresShellResolution.
+   */
+  float ComputeIntrinsicResolution() const;
+
+  /* The only direct calls to this should be in test code.
+   * Normally, it gets called by HandleEvent().
+   */
+  void HandleDOMMetaAdded();
+
+ private:
+  void SetRestoreResolution(float aResolution);
+
+ public:
+  /* Notify the MobileViewportManager that a reflow is about to happen. This
+   * triggers the MVM to update its internal notion of display size and CSS
+   * viewport, so that code that queries those during the reflow gets an
+   * up-to-date value.
+   */
+  void UpdateSizesBeforeReflow();
+
+  /* Notify the MobileViewportManager that a reflow was requested in the
+   * presShell.*/
+  void RequestReflow(bool aForceAdjustResolution);
+
+  /* Notify the MobileViewportManager that the resolution on the presShell was
+   * updated, and the visual viewport size needs to be updated. */
+  void ResolutionUpdated(mozilla::ResolutionChangeOrigin aOrigin);
+
+  /* Called to compute the initial viewport on page load or before-first-paint,
+   * whichever happens first. Also called directly if we are created after the
+   * presShell is initialized. */
+  void SetInitialViewport();
+
+  const mozilla::LayoutDeviceIntSize& DisplaySize() const {
+    return mDisplaySize;
+  };
+
+  /*
+   * Shrink the content to fit it to the display width if no initial-scale is
+   * specified and if the content is still wider than the display width.
+   */
+  void ShrinkToDisplaySizeIfNeeded();
+
+  /*
+   * Similar to UpdateVisualViewportSize but this should be called only when we
+   * need to update visual viewport size in response to dynamic toolbar
+   * transitions.
+   * This function doesn't cause any reflows, just fires a visual viewport
+   * resize event.
+   */
+  void UpdateVisualViewportSizeByDynamicToolbar(
+      mozilla::ScreenIntCoord aToolbarHeight);
+
+  nsSize GetVisualViewportSizeUpdatedByDynamicToolbar() const {
+    return mVisualViewportSizeUpdatedByDynamicToolbar;
+  }
+
+  /*
+   * This refreshes the visual viewport size based on the most recently
+   * available information. It is intended to be called in particular after
+   * the root scrollframe does a reflow, which may make scrollbars appear or
+   * disappear if the content changed size.
+   */
+  void UpdateVisualViewportSizeForPotentialScrollbarChange();
+
+  /*
+   * Returns the composition size in CSS units when zoomed to the intrinsic
+   * scale.
+   */
+  mozilla::CSSSize GetIntrinsicCompositionSize() const;
+
+  mozilla::ParentLayerSize GetCompositionSizeWithoutDynamicToolbar() const;
+
+  static mozilla::LazyLogModule gLog;
+
+ private:
+  ~MobileViewportManager();
+
+  /* Main helper method to update the CSS viewport and any other properties that
+   * need updating. */
+  void RefreshViewportSize(bool aForceAdjustResolution);
+
+  /* Secondary main helper method to update just the visual viewport size. */
+  void RefreshVisualViewportSize();
+
+  /* Helper to clamp the given zoom by the min/max in the viewport info. */
+  mozilla::CSSToScreenScale ClampZoom(
+      const mozilla::CSSToScreenScale& aZoom,
+      const nsViewportInfo& aViewportInfo) const;
+
+  /* Helper to update the given zoom according to changed display and viewport
+   * widths. */
+  mozilla::CSSToScreenScale ScaleZoomWithDisplayWidth(
+      const mozilla::CSSToScreenScale& aZoom,
+      const float& aDisplayWidthChangeRatio,
+      const mozilla::CSSSize& aNewViewport,
+      const mozilla::CSSSize& aOldViewport);
+
+  mozilla::CSSToScreenScale ResolutionToZoom(
+      const mozilla::LayoutDeviceToLayerScale& aResolution) const;
+  mozilla::LayoutDeviceToLayerScale ZoomToResolution(
+      const mozilla::CSSToScreenScale& aZoom) const;
+
+  /* Updates the presShell resolution and the visual viewport size for various
+   * types of changes. */
+  void UpdateResolutionForFirstPaint(const mozilla::CSSSize& aViewportSize);
+  void UpdateResolutionForViewportSizeChange(
+      const mozilla::CSSSize& aViewportSize,
+      const mozilla::Maybe<float>& aDisplayWidthChangeRatio);
+  void UpdateResolutionForContentSizeChange(
+      const mozilla::CSSSize& aContentSize);
+
+  void ApplyNewZoom(const mozilla::ScreenIntSize& aDisplaySize,
+                    const mozilla::CSSToScreenScale& aNewZoom);
+
+  void UpdateVisualViewportSize(const mozilla::ScreenIntSize& aDisplaySize,
+                                const mozilla::CSSToScreenScale& aZoom);
+
+  /* Updates the displayport margins for the presShell's root scrollable frame
+   */
+  void UpdateDisplayPortMargins();
+
+  /* Helper function for ComputeIntrinsicResolution(). */
+  mozilla::CSSToScreenScale ComputeIntrinsicScale(
+      const nsViewportInfo& aViewportInfo,
+      const mozilla::ScreenIntSize& aDisplaySize,
+      const mozilla::CSSSize& aViewportOrContentSize) const;
+
+  /*
+   * Returns the screen size subtracted the scrollbar sizes from |aDisplaySize|.
+   */
+  mozilla::ScreenIntSize GetCompositionSize(
+      const mozilla::ScreenIntSize& aDisplaySize) const;
+
+  mozilla::CSSToScreenScale GetZoom() const;
+
+  RefPtr<mozilla::MVMContext> mContext;
+  ManagerType mManagerType;
+  bool mIsFirstPaint;
+  bool mPainted;
+  mozilla::LayoutDeviceIntSize mDisplaySize;
+  mozilla::CSSSize mMobileViewportSize;
+  mozilla::Maybe<float> mRestoreResolution;
+  mozilla::Maybe<mozilla::ScreenIntSize> mRestoreDisplaySize;
+  /*
+   * The visual viewport size updated by the dynamic toolbar transitions. This
+   * is typically used for the VisualViewport width/height APIs.
+   * NOTE: If you want to use this value, you should make sure to flush
+   * position:fixed elements layout and update
+   * FrameMetrics.mFixedLayerMargins to conform with this value.
+   */
+  nsSize mVisualViewportSizeUpdatedByDynamicToolbar;
+};
+
+#endif